v12.0.0 - initial commit

packages/server/lib/plugins/ticker/ccxt.js

@@ -0,0 +1,77 @@
+const ccxt = require('ccxt')
+
+const BN = require('../../bn')
+const {
+  buildMarket,
+  verifyFiatSupport,
+  defaultFiatMarket,
+} = require('../common/ccxt')
+const { getRate } = require('../../../lib/forex')
+
+const RETRIES = 2
+
+const tickerObjects = {}
+
+// This is probably fixed on upstream ccxt
+// but we need to udpate node to get on the latest version
+const sanityCheckRates = (ask, bid, tickerName) => {
+  if (new BN(0).eq(ask) || new BN(0).eq(bid)) {
+    throw new Error(`Failure fetching rates for ${tickerName}`)
+  }
+}
+
+function ticker(fiatCode, cryptoCode, tickerName) {
+  if (!tickerObjects[tickerName]) {
+    tickerObjects[tickerName] = new ccxt[tickerName]({
+      timeout: 3000,
+      enableRateLimit: false,
+    })
+  }
+
+  const ticker = tickerObjects[tickerName]
+
+  if (verifyFiatSupport(fiatCode, tickerName)) {
+    return getCurrencyRates(ticker, fiatCode, cryptoCode)
+  }
+
+  return getRate(RETRIES, fiatCode, defaultFiatMarket(tickerName)).then(
+    ({ fxRate }) => {
+      try {
+        return getCurrencyRates(
+          ticker,
+          defaultFiatMarket(tickerName),
+          cryptoCode,
+        ).then(res => ({
+          rates: {
+            ask: res.rates.ask.times(fxRate),
+            bid: res.rates.bid.times(fxRate),
+          },
+        }))
+      } catch (e) {
+        return Promise.reject(e)
+      }
+    },
+  )
+}
+
+function getCurrencyRates(ticker, fiatCode, cryptoCode) {
+  try {
+    if (!ticker.has['fetchTicker']) {
+      throw new Error('Ticker not available')
+    }
+    const symbol = buildMarket(fiatCode, cryptoCode, ticker.id)
+    return ticker.fetchTicker(symbol).then(res => {
+      sanityCheckRates(res.ask, res.bid, cryptoCode)
+      return {
+        rates: {
+          ask: new BN(res.ask),
+          bid: new BN(res.bid),
+        },
+      }
+    })
+  } catch (e) {
+    return Promise.reject(e)
+  }
+}
+
+module.exports = { ticker }